1. Field of the Invention
The present invention relates to indoor communications wireless distribution systems in general, and more particularly to interference reduction in an indoor communications wireless distribution system.
2. Discussion of the Related Art
Recently, the indoor deployment of wireless antenna networks, such as cellular networks or wireless LAN networks, is increasingly becoming a widespread phenomenon in the world of communications. Such wireless antenna networks are specifically deployed in large man-made structures such as multi-store office buildings, large shopping malls, parking garages (both underground and above ground), apartment buildings, residential homes, and distant structures. The indoor deployment provides for the operation of a wireless distribution system for areas that either lack signal or lack the required signal strength for adequate sufficient communication performance. The objectives of an indoor deployment regard both the provision of enhanced and extended wireless communications services to the subscribers of a communications network operating within large man-made structures where the network coverage is reduced or non-existent, and the increase of the capacity of the network in crowded areas where the number of potential service users is high, such as in entertainment centers, transportation hubs, hospital multi-buildings, university campuses, and commercial complexes.
Two conventional configurations are typically being used in order to provide extended or enhanced wireless coverage to structures having large indoor areas. The first configuration is characterized by the utilization of a repeater device and the service is provided by a donor site that is located in close proximity of the coverable structure. An external antenna is installed in the coverable structure at a suitable location. The external antenna receives and broadcasts signals from and to the external donor site. The external antenna is connected to one or more internal antennas installed within the internal space of the coverable structure via an bi-directional amplifier device. Thus, the downlink signals received from the external donor site by the external antenna are amplified and distributed within the internal space of the coverable structure to the internal antennas. The internal antennas broadcast the signals across the internal space of the coverable structure to the customer communication devices, such as s cellular phones. The uplink signals generated by the customer communication devices operating within the internal space of the coverable structure are received by the internal antennas, fed to the external antenna and broadcasted by the external antenna to the external donor site.
In the second type of configuration no use is made of a donor site. Instead, the donor site/external antenna is replaced by a fill Radio Base Station (RBS) that is installed in the coverable structure. The RBS consists of radio transmitter and a receiver that permit propagation of signals among wireless user devices (such as cellular phones) within the structure. The RBS is connected to a network of internally installed antennas within the internal space of the coverable structure via a bi-directional amplifier device in a manner similar to the first configuration.
In the typical configuration the wireless signals, such as cellular signals) are divided (split) among several inter-connected internally installed antennas. The inter-connected internal antennas are coupled to the repeater device or the Radio Base Station (RBS) via RF cables or optical fibers. As a result of the inter-connectedness, if one or more of the internal antennas receive a noisy signal, such as, for example, an interference generated by specific electronic components or by specific computing devices operating in the structure, the interfering signal may effect the disruption or the blocking of the reception of the signals from the entire set of the internal antennas. Such interferences are enhanced through the fact that the signals received from the antennas are summed together. Thus, an interference created by one antenna can block signals received from other antennas located within said structure. In addition, in the first deployment configuration in which the service is provided by a donor station and a repeater is installed in the structure, the interfering signals may be amplified and transmitted through the air interface to the donor station and thereby could generate a disruption or blockage of the wireless signals across a wider area.
Therefore, it would be easily perceived by one with ordinary skills in the art that a novel system and method is required in order to provide a substantial reduction in the distribution of local interferences, generated in micro-cell/pico-cell or network cells associated with a specific indoor deployment segment of a communication network where the interference is received by an antenna servicing a coverable structure, to the wider network. The reduction of the interference should provide the proper reception of suitably noise-free wireless signals from other associated antennas, and should prevent a situation in which the interference will disrupt and block the proper reception and transmission of the wireless signals across a wider area outside the internal space of the structure.